title: Vitamin D, race, and risk for anemia in children.
abstract: OBJECTIVE
  To examine the association between 25-hydroxyvitamin D [25(OH)D] deficiency and anemia in a cohort of otherwise-healthy children and to determine whether race modifies the association between 25(OH)D status and hemoglobin (Hgb).
  
  
  METHODS
  Cross-sectional study of 10,410 children and adolescents ages 1-21 years from the 2001-2006 National Health and Nutrition Examination Survey. Anemia was defined as Hgb less than the 5th percentile for age and sex based on National Health and Nutrition Examination Survey III (1988-1994) data.
  
  
  RESULTS
  Lower 25(OH)D levels were associated with increased risk for anemia; <30 ng/mL, adjusted OR 1.93, 95% CI 1.21-3.08, P = .006, and <20 ng/mL, OR 1.47, 95% CI 1.14-1.89, P = .004. In linear regression, small but significant increases in Hgb were noted in the upper quartiles of 25(OH)D compared with the lowest quartile (<20 ng/mL) in the full cohort. Results of race-stratified linear regression by 25(OH)D quartile in white children were similar to those observed in the full cohort, but in black children, an increase in Hgb in the upper 25(OH)D quartiles was only apparent compared with the lowest black race-specific quartile (<12 ng/mL).
  
  
  CONCLUSIONS
  25(OH)D deficiency is associated with increased risk of anemia in healthy US children, but the 25(OH)D threshold levels for lower Hgb are lower in black children in comparison with white children.
authors.affiliation: Division of Pediatric Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD. Electronic address: matkins3@jhmi.edu.
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Atkinson
authors.affiliation: Departments of Medicine and Epidemiology & Population Health, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Michal L
authors.initials: ML
authors.lastname: Melamed
authors.affiliation: Division of Pediatric Nephrology, Weill Cornell Medical College, New York, NY.
authors.forename: Juhi
authors.initials: J
authors.lastname: Kumar
authors.affiliation: Divisions of Hematology and Geriatric Medicine and Gerontology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Cindy N
authors.initials: CN
authors.lastname: Roy
authors.affiliation: Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Edgar R
authors.initials: ER
authors.lastname: Miller
authors.affiliation: The Children's Hospital of Philadelphia, Philadelphia, PA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Furth
authors.affiliation: Division of Pediatric Nephrology, Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fadrowski
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000740:Anemia / Q000097:blood / Q000208:ethnology* / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009749:Nutrition Surveys; D044469:Racial Groups; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000208:ethnology*; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: 25(OH)D; 25-Hydroxyvitamin D; BMI; Body mass index; C-reactive protein; CDC; CKD; CRP; Centers for Disease Control and Prevention; Chronic kidney disease; ESA; Erythropoiesis-stimulating agent; GFR; Glomerular filtration rate; Hemoglobin; Hgb; NHANES; National Health and Nutrition Examination Survey; TIBC; Total iron-binding capacity